Bile Acids Show Promise as Feed Additives in Aquaculture

Strategic Insights -

Researchers from Alexandria University have found that adding commercial bile acids to the diet of Nile tilapia (Oreochromis niloticus) enhances growth performance, nutrient assimilation, and immune responses, while also promoting the expression of genes involved in lipid metabolism. The study, which was funded by the Arab Academy For Science, Technology & Maritime Transport, aimed to evaluate the impact of bile acid supplementation on the fish's physiological and biochemical parameters.

Key Takeaways:

  • The study evaluated the effect of dietary addition of commercial bile acids on growth, nutrient assimilation, immunity, antioxidant status, intestinal and hepatic histomorphometry, and gene expression of lipid metabolism in Nile tilapia.
  • The fish were fed a diet enriched with varying amounts of bile acids (0.0, 0.1, 0.2, 0.3, 0.4, and 0.5 g/kg) for 70 days.
  • The results showed that Nile tilapia fed a diet with 0.2 g/kg of bile acids exhibited significantly enhanced growth performance, with a specific growth rate of 1.89%/day, and had the greatest feed conversion ratio (1.25) and energy utilization (33.28%).
  • The study found that dietary 0.2 g/kg bile acids supplementation positively influenced physiological, biochemical parameters, and lipid metabolic of Nile tilapia.
  • Gene expression related to lipid metabolism in liver, peritoneal fat, and muscle tissues was upregulated in the treatment groups, especially in those receiving 0.2 g/kg bile acids.
  • Carnitine palmitoyl transferase 1 (CPT-1) and Insulin-like growth factor-II (Igf-II) expression declined, particularly when the bile acids dose was increased.

Statistics:

  • The study used 180 healthy fingerprinting weighing 9 ± 0.5 g.
  • The 70-day study consisted of 18 hapas measuring 0.7 x 0.7 x 1.0 m.
  • Energy content varied significantly, with D1 showing the lowest value (533.34 Kcal/100 g) and D3 the highest (604.27 Kcal/100 g).
  • The specific growth rate of Nile tilapia fed the D3 diet was 1.89%/day.
  • The feed conversion ratio (FCR) of fish fed the D3 diet was 1.25.
  • The protein productive value and energy utilization of fish fed the D3 diet were 33.28%.

Sources:

  • "Impacts of commercial bile acids on growth performance, immune responses and expression genes of lipid metabolism in Nile tilapia fingerlings Oreochromis niloticus" (Scientific Reports, 2025, 15(1):1-17)
  • Yasser Marzouk, Animal Production Department, Faculty of Agriculture, Alexandria University
  • Mohamed Abdullah Zaki, Abd-Elaziz M. Nour, Ahmed Ismail Mehrim, Hala Saber Khalil (Additional authors)
  • Arab Academy For Science, Technology & Maritime Transport (Funder)
  • Alexandria University
  • Nature Portfolio (Publisher)
  • https://doi-org.sdpl.idm.oclc.org/10.1038/s41598-025-06813-0
  • Life Science Weekly (News Report)